Optimization of multi response in end milling process of ASSAB XW-42 tool steel with liquid nitrogen cooling using taguchi grey-fuzzy method

A research was conducted for the optimization of the end milling process of ASSAB XW-42 tool steel with multiple performance characteristics based on the orthogonal array with Taguchi-grey-fuzzy method. Liquid nitrogen was applied as a coolant. The experimental studies were conducted under varying the liquid nitrogen cooling flow rate (FL), and the end milling process variables, i.e., cutting speed (V_c), feeding speed (V_f) and axial depth of cut (A_a). The optimized multiple performance characteristics were surface roughness (SR), flank wear (VB) and material removal rate (MRR). An orthogonal array, signal-to-noise (S/N) ratio, grey relational analysis, grey-fuzzy reasoning grade and analysis of variance were employed to study the multiple performance characteristics. Experimental results show that flow rate gives the highest contribution for reducing the total variation of the multiple responses, followed by cutting speed, feeding speed and axial depth of cut. The minimum surface roughness, flank wear and maximum material removal rate could be obtained by using the values of flow rate, cutting speed, feeding speed and axial depth of cut of 0.5 l/minute, 109.9 m/minute, 94.2 mm/minute, and 0.9 mm respectively.